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Candidate passed pawns

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Detect safe candidate passers.

STC: http://tests.stockfishchess.org/tests/view/5882395c0ebc5915193f78b3
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 53569 W: 9925 L: 9570 D: 34074

LTC: http://tests.stockfishchess.org/tests/view/5882b4fb0ebc5915193f78e2
LLR: 2.95 (-2.94,2.94) [0.00,5.00]
Total: 77576 W: 10387 L: 10014 D: 57175

Bench: 5325829
This commit is contained in:
Stefan Geschwentner
2017-01-19 18:16:23 +01:00
committed by Marco Costalba
parent 58c181de9a
commit 471f7a1b5c
2 changed files with 20 additions and 8 deletions
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13
src/pawns.cpp
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@@ -99,8 +99,9 @@ namespace {
const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
Bitboard lever, leverPush, connected;
Square s;
bool opposed, lever, connected, backward;
bool opposed, backward;
Score score = SCORE_ZERO;
const Square* pl = pos.squares<PAWN>(Us);
const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
@@ -129,6 +130,7 @@ namespace {
opposed = theirPawns & forward_bb(Us, s);
stoppers = theirPawns & passed_pawn_mask(Us, s);
lever = theirPawns & pawnAttacksBB[s];
leverPush = theirPawns & pawnAttacksBB[s + Up];
doubled = ourPawns & (s + Up);
neighbours = ourPawns & adjacent_files_bb(f);
phalanx = neighbours & rank_bb(s);
@@ -153,8 +155,13 @@ namespace {
}
// Passed pawns will be properly scored in evaluation because we need
// full attack info to evaluate them.
if (!stoppers && !(ourPawns & forward_bb(Us, s)))
// full attack info to evaluate them. Include also not passed pawns
// which could become passed after one or two pawn pushes when are
// not attacked more times than defended.
if ( !(stoppers ^ lever ^ leverPush)
&& !(ourPawns & forward_bb(Us, s))
&& popcount(supported) >= popcount(lever)
&& popcount(phalanx) >= popcount(leverPush))
e->passedPawns[Us] |= s;
// Score this pawn